New Era of ST 2110 Testing With PICS and RP 2110-25

Presenters : Ievgen Kostiukevych - EBU

Year : 2022

dlp_document_download : New Era of ST 2110 Testing with PICS and RP 2110-25 Willem Vermost Pavlo Kondratenko wim.vermost@vrt.be kondratenko@ebu.ch JT-NM Tested program EBU TECHNOLOGY & INNOVATION SEPTEMBRE 2022 © IBC 2022 - IP SHOWCASE IP Showcase Pavlo Kondratenko - Willem Vermost What JT-NM Tested? The JT-NM Tested program offers documented insight into how vendor equipment conforms to specific SMPTE standards and AMWA NMOS specifications. Vendors who meet the testing criteria will have the opportunity to display badges and make public statements about their participation. The JT-NM Tested Catalog lists vendor results along with a detailed test plan. Anyone with the equipment listed in the test plan may execute the tests which were administered by the JT-NM test team, and you are encouraged to do so. It is important to note that the JT-NM Tested program is not a certification program; rather, it is a snapshot in time of how vendor equipment conforms to key parts of SMPTE standards and AMWA NMOS specifications. AUGUST 2022 JT-NM Tested PROGRAM style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y style.visibility style.visibility The road towards the tested event While drafting the standard, early T&M solutions came available Multiple "Dirty hands" events were held to check the theory in real-life IP showcase: technology demonstrator IBC 2017: SMPTE ST 2110 officially published From "dirty hands" to JT-NM Tested event A tested event needs two major things: Test & Measurement equipment A set of tests to perform What are the 2 problems? Moving from creating the document to a published standard, measurement tools were already available. As a result, not using the same nomenclature for certain measurements and even not the same formulas . (SMPTE RP 2110-25) When creating the test document what tests are applicable? Sometimes it was hard to figure out, even amongst top experts, what specific part of the standard is mandatory and what’s not? The PICS work brings a solution. What’s the 1 st problem? During the 2019 JT-NM Tested Event in Houston, the test team had access to a variety of test equipment, each with his or her specific specialty but also a fair amount of overlap of measurements. The overlapping measurements were conveniently used to ensure consistency of test and measurement equipment on the one hand, but also to simply have confirmation of the measurement on the other. It didn't take much time or the test team had to deal with a Babylonian confusion. Most of the test kit had been created in parallel with the writing of the SMPTE ST 2110 standard suite. Since nomenclature and formulas may be in flux until the document is published, or simply do not specify a practical test for a particular concept being introduced; not all test and measurement kits use exactly the same nomenclature or formulas that probably should do the same thing. Avoiding Babylonian Confusion WHAT ARE WE FIXING? Agree on a set of measurements Agree on some naming conventions Agree on the formulas N S R style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y style.visibility style.visibility style.visibility style.visibility Avoiding Babylonian Confusion WHAT ARE WE FIXING? Agree on a set of measurements Agree on some naming conventions Agree on the formulas style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y EBU TECHNOLOGY & INNOVATION Gapped Packet Read Schedule   N   ∗   T FRAME Since Epoch     ( N +1)  ∗   T FRAME Since Epoch     T VD     T VD     T RS ( gapped )     TP 𝑅 0     TP 𝑅 j   TR OFFSET t   TP 𝐴 0     TP 𝐴 j   FPT   TP 𝐴 n − 1   Marker Bit Set FPT RTP Timestamp = x Packet Arrival Virtual Receive Buffer Margin t t N PACKETS * T RS(gapped) TR OFFSET   TP 𝑅 n −1   Packet Arrival GAP   TP 𝐴 0     TP 𝑅 0   Steady State Window Full Window Read GAP = TVD – TPRn-1( CF-1) Work in Progress style.visibility style.visibility style.visibility style.visibility ppt_x ppt_y EBU TECHNOLOGY & INNOVATION Gapped Packet Read Schedule   N   ∗   T FRAME Since Epoch     ( N +1)  ∗   T FRAME Since Epoch     T VD     T VD     T RS ( gapped )     TP 𝑅 0     TP 𝑅 j   TR OFFSET t   TP 𝐴 0     TP 𝐴 j   FPT   TP 𝐴 n − 1   Marker Bit Set FPT RTP Timestamp = x Packet Arrival Virtual Receive Buffer Margin t t N PACKETS * T RS(gapped) TR OFFSET   TP 𝑅 n −1   Packet Arrival GAP   TP 𝐴 0     TP 𝑅 0   Steady State Window Full Window Read GAP = TVD – TPRn-1( CF-1) Video Timing, Video to PTP, PTP to Video, First Packet Timing, First Packet Offset, Stream Timing, … FPT = TP A 0 – N * T FRAME TR OFFSET is the difference between the most recent integer multiple of T FRAME and T VD . Work in Progress style.visibility style.visibility style.visibility style.visibility style.visibility ppt_x ppt_y EBU TECHNOLOGY & INNOVATION Gapped Packet Read Schedule   N   ∗   T FRAME Since Epoch     ( N +1)  ∗   T FRAME Since Epoch     T VD     T VD     T RS ( gapped )     TP 𝑅 0     TP 𝑅 j   TR OFFSET t   TP 𝐴 0     TP 𝐴 j   FPT   TP 𝐴 n − 1   Marker Bit Set FPT RTP Timestamp = x Packet Arrival Virtual Receive Buffer Margin t t N PACKETS * T RS(gapped) TR OFFSET   TP 𝑅 n −1   Packet Arrival GAP   TP 𝐴 0     TP 𝑅 0   Steady State Window Full Window Read GAP = TVD – TPRn-1( CF-1) Buffer Model Prefill, Buffer Margin, Buffer Target (express in packets?), Presentation Time Headroom Margin = (N * T FRAME + TR OFFSET ) – TP A 0 Work in Progress style.visibility style.visibility style.visibility style.visibility ppt_x ppt_y Avoiding Babylonian speech confusion MEASURING 2110-21 C PEAK shall not exceed C MAX VRX PEAK shall not exceed VRX FULL No formulas, but algorithms. More fun! def cfull_analysis (capture, tframe , npackets , B): cpeak = 0 # Initialize the C peak value cinst = 0 # Initialize the C inst value tcurr = None # Tcurr as Time of the current packet tprev = None # Tprev as Time of the previous packet   # Calculate Tdrain as defined in SMPTE ST 2110-21 tdrain = tframe / npackets / Decimal(B)   for pkt in capture: tcurr = Decimal( pkt.time ) if tprev : cinst += 1 cinst -= ( tcurr - tprev )/ tdrain if cinst < 0: cinst = 0 tprev = tcurr if cinst > cpeak : cpeak = math.ceil ( cinst ) return cpeak Bursts and jitter could potentially lead to packet loss in the network. Therefore, jeopardizing the reliability of the solution. SMPTE ST 2110-21 introduced a leaky bucket with a maximum level (CMAX) to prevent packet loss in the network. style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y style.visibility style.visibility style.visibility RP2110-25 EBU TECHNOLOGY & INNOVATION MEASURING 2110-21 C PEAK shall not exceed C MAX VRX PEAK shall not exceed VRX FULL No formulas, but algorithms. More fun! style.visibility ppt_x ppt_y style.visibility style.visibility ppt_x ppt_y style.visibility ppt_x ppt_y EBU LIST 2. 2 style.visibility style.visibility style.visibility style.visibility What is a PICS? A Protocol Implementation Conformance Statement ( PICS ) is a structured document which asserts which specific requirements are met by a given implementation of a protocol standard. AES67-2018 was the first revision of the AES67 standard to include PICS for this standard. We used it as an example. PICS Benefits Helps implementers by providing a checklist of requirements Helps implementers by providing additional clarifications to some of the requirements Helps users by listing all the requirements and exact options that were implemented Helps users ensure interoperation between two implementations PICS Benefits Helps in procurement - might be utilized for tender procedures Helps in testing – provides a basis for preparing tests to be used to determine conformance of an implementation to the standard. Will be used in JTNM-Tested. SMPTE ST 2110 PICS Format: Separate document – Recommended Practice Naming: Number of the original document plus 100: Pics for ST 2110-10 is in RP 2110-110 SMPTE ST 2110 PICS Structure: Follows the original document, statement by statement, each statement is numbered Each requirement level is color-coded and numbered SMPTE ST 2110 PICS The core of the proforma: The statement number The statement from the ST2110 document Requirement level "Notes" column with criteria for making the decision. Eventually comments or further clarifications of original document’s statement are also provided here "Supported" column with the decision in "Yes/No" format SMPTE ST 2110 PICS Statements applicable only to a subset of implementations: The additional question that strictly defines if the statement is applicable to the implementation A special color for the requirement level to differentiate between the strongest "shall" statements that apply to all implementations and those that apply only to a subset of implementations Conclusions Number of practical problems have emerged Addressed with JT-NM Tested SMPTE PICS ST 2110-25 Any Questions?